Control unit

ABSTRACT

In order to improve a control unit for operating a refrigerant compressor system, wherein the refrigerant compressor system has a first refrigerant line system for expanded refrigerant, a second refrigerant line system for compressed refrigerant, and at least one refrigerant compressor, which operates between the first refrigerant line system and the second refrigerant line system and is driven by its own motor, and wherein the control unit has an operating unit, such that it is operable in a user-friendly manner, it is proposed that the operating unit should have a memory for image element data, for representing at least one component of the refrigerant compressor system, that the operating unit should have a display unit which, using the image element data of the at least one component of the refrigerant compressor system, displays this at least one component on the display unit, as a component image element.

CROSS-REFERENCE TO RELATED PATENT APPLICATION

This application is a continuation of International application numberPCT/EP2016/054905 filed on Mar. 8, 2016.

This patent application claims the benefit of International applicationNo. PCT/EP2016/054905 of Mar. 8, 2016 and German application No. 10 2015103 729.7 of Mar. 13, 2015, the teachings and disclosure of which arehereby incorporated in their entirety by reference thereto.

BACKGROUND OF THE INVENTION

The invention relates to a control unit for operating a refrigerantcompressor system, wherein the refrigerant compressor system has a firstrefrigerant line system for expanded refrigerant and a secondrefrigerant line system for compressed refrigerant from at least onerefrigerant compressor, which operates between the first refrigerantline system and the second refrigerant line system and is driven by itsown motor, wherein the control unit has an operating unit.

Control units of this kind are known from the prior art, but theoperation of these using the conventional keys is complex and notuser-friendly.

The object of the invention is therefore to improve a control unit ofthe generic type such that it is operable in a user-friendly manner.

SUMMARY OF THE INVENTION

This object is achieved according to the invention in the case of acontrol unit of the type mentioned in the introduction in that theoperating unit has a memory for image element data, for representing atleast one component of the refrigerant compressor system, in that theoperating unit has a display unit which, using the image element data ofat least one of the components of the refrigerant compressor system,displays the at least one component on this display unit, as a componentimage element.

The advantage of the solution according to the invention lies in thefact that it opens up the possibility of representing on the displayunit at least one component or a plurality of components of therefrigerant compressor system, and thus simplifying a readilycomprehensible user interface for the operation thereof and making itmore transparent and more clearly laid out for an operating person.

The components of the refrigerant compressor system may be of the mostdiverse types.

Thus one solution provides for the component to include at least onerefrigerant compressor, and, using the image element data of the atleast one refrigerant compressor, for the operating unit to representthis refrigerant compressor on the display unit, as a compressor imageelement.

Here, a compressor image element of this type may take the most diverseforms.

For example, it is provided for the respective compressor image elementto be a realistic image of the respective refrigerant compressor thatmakes it more easily recognisable for an operating person.

As an alternative thereto, it is provided for the respective compressorimage element to be a stylised image of the respective refrigerantcompressor.

In principle, however, it is also possible for the respective compressorimage element to be a symbol of the respective refrigerant compressor.

A further advantageous alternative provides for the component to includeat least one refrigerant line, and, using the image element data of therefrigerant line, for the operating unit to represent the refrigerantline on the display unit, as a line image element.

The most diverse possibilities are likewise conceivable as regards theline image element.

Thus, an advantageous solution provides for the respective line image tobe a realistic image of the at least one refrigerant line.

As an alternative thereto, however, it would also be conceivable for therespective line element to be a stylised image of the at least onerefrigerant line.

Further, however, it would also be conceivable in principle for therespective line image element to be a symbol of the respectiverefrigerant line.

Further, another advantageous alternative provides for the component ofthe refrigerant compressor system to include a at least one sensor, and,using the image element data of the at least one sensor, for theoperating unit to represent the sensor on the display unit, as a sensorimage element.

The most diverse possibilities are also conceivable as regards thesensor image element.

For example, it would be conceivable for the sensor image element to bea realistic representation of the sensor.

As an alternative thereto, it is advantageous for the sensor imageelement to be an image element that represents the respective sensor instylised form, wherein an image element of this kind that represents therespective sensor in stylised form has the advantage that the existenceof the sensor is represented with sufficient precision but on the otherhand a large quantity of data is not required for representing the imageelement.

Further, however, it is likewise conceivable in principle for the sensorimage element to be an image element that represents the respectivesensor symbolically and requires an even smaller quantity of data forthe representation.

Further, in the representation of a sensor image element it is providedfor the operating unit to have a memory for sensor data, and for theoperating unit to represent the sensor data on the display unit.

Thus, the sensor data are available to an operating person in a simplemanner.

In particular, it is favourable if the operating unit represents thesensor data on the display unit together with the sensor image element.

This solution has the major advantage that in this case the operatingperson can also simultaneously take in the sensor data in conjunctionwith the sensor image element.

Here, the term “sensor data” should be understood to mean any datarequired in conjunction with the sensor.

This means that the sensor data may either be a specification of thesensor itself or indeed sensor values.

It is preferably provided for the sensor values that are detected by thesensors to be represented as a part of the sensor data, for example withthe sensor image element.

In particular, it is provided for the sensor values to be represented bya display element of the sensor image element.

In particular, it is provided for the respective sensor image element tobe an image element having a display field for the respective sensorvalue measured by the sensor.

This means that for example the sensor image has a scale and the displayelement is represented as a pointer that indicates the sensor value inthat the pointer points to the respective numerical value on the scale.

As an alternative thereto, it is preferably provided for the sensorvalues to be represented numerically in the sensor image element.

More detailed statements have not yet been made as regards the locationof the representation of the respective sensor image element.

In principle, the respective sensor image element could be representedat any desired location on the display unit.

A particularly advantageous solution provides for the sensor imageelement to be represented at the location of the refrigerant compressorsystem at which the sensor detects the respective sensor value.

A further advantageous embodiment of the solution according to theinvention provides for the component to be include at least one actuatorof the refrigerant compressor system, and, using the image element dataof the at least one actuator, for the operating unit to represent thisactuator on the display unit, as an actuator image element.

Here, the term “actuators” should be understood to mean any componentsof the refrigerant compressor system that bring about or control afunction.

In the case of an actuator, it is particularly advantageous if theoperating unit has a memory for actuator data, and if the operating unitrepresents the actuator data on the display unit.

In this case, it is particularly advantageous if the actuator data arerepresented in a manner associated with the actuator image element.

Here, it is conceivable for example for the actuator data to berepresented by a display element.

As an alternative thereto, it is provided for the actuator data to berepresented numerically.

As an alternative or in addition to the embodiments of the control unitaccording to the invention that have been described above, a furtheradvantageous embodiment provides for the operating unit to have a memoryfor image element data for the purpose of representing at least oneoperating state of the refrigerant compressor system, and, using theimage element data of the at least one operating state of therefrigerant compressor system, for the operating unit to display the atleast one operating state of the refrigerant compressor system on thedisplay unit, as a state image element.

A display of the operating states of this kind may take place in themost diverse ways.

For example, it is conceivable for the state image element to berepresented in conjunction with the respective component image elementwith which the operating state are associated.

For example, it would be conceivable to provide as the state imageelement a coloured background for the respective component imageelement, such that for example the respective operating state isrepresented by the coloured background of red or green in the respectivecomponent image element.

As an alternative thereto, however, it is also conceivable to representthe state image element by a graphical symbol in the respectivecomponent image element or alongside the respective component imageelement.

As an alternative or in addition thereto, a further solution providesfor the state image element to be represented as a state field that isassociated with the individual component image element.

As an alternative or in addition to the solutions above, a furtheradvantageous solution provides for the operating unit to have a memoryfor image element data for the purpose of representing at least oneoperating element of the operating unit, and, using the image elementdata of the at least one operating element of the operating unit, forthe operating unit to display the at least one operating element on thedisplay unit, as an operating element image element.

Further, it is preferably provided for the memory to have image elementdata for representing at least one operating state of the respectiveoperating element of the operating unit, and, using the image elementdata of the at least one operating state of the respective operatingelement, for the operating unit to display the at least one operatingstate of the operating element on the display unit, as an operatingstate image element.

Here, the operating state element may be represented in the most diverseways.

Thus, an advantageous solution provides for the operating state imageelement to be represented on the display unit in a manner associatedwith the respective operating element image element.

However, it is also conceivable to represent the operating state elementindependently of the operating element image element, for example in theform of an additional signal element.

In conjunction with the description above of the solution according tothe invention, more detailed statements have not been made as regardsthe construction of the display unit and the interaction with thedisplay element.

Thus, an advantageous solution provides for the display unit to take aform such that, as a result of a manual interaction with one of therepresented image elements of the operating unit, a command isproducible.

This means that the manual interaction results in a defined command thatis directed to and transmitted to the display unit and/or the operatingunit and/or the control unit.

The manual interaction here may consist in moving a cursor to the imageelement and making the manual interaction for example by a mouse clicksuch that the command is thereby generated and in particular can also betransmitted.

A particularly advantageous solution provides for the display unit totake the form of a touch-detecting display unit, in particular atouch-sensitive surface, and for the manual interaction to be performedby manually touching the surface of the display unit in the region ofthe image element represented on the display unit.

A display unit of this kind in particular takes the form of a so-calledtouchscreen, with the result that the manual interactions can be theusual interactions provided for with a touchscreen.

Manual interactions of this kind may be tapping or swiping, for examplein the horizontal or vertical direction, or indeed making larger orsmaller by the relative movement of two touch points in relation to oneanother, that is to say moving two touch points apart or together.

Here, the command that is generated and transmitted may be of the mostdiverse types.

Thus, one solution provides for the command, in particular inconjunction with an operating element, to be a command for activating ordeactivating or changing an action.

As an alternative thereto, however, it is also conceivable for thecommand to serve to change the representation, for example to call up adifferent representation or a further representation.

Here, is further representation may be a changed representation of thesame or a further image element.

However, it is also provided for the further representation function tobe an enlarged representation of the same image element.

A further possibility provides for the further representation of therespective image element to be a representation of the respective imageelement with further image elements.

More detailed statements have not been made as regards the interactionbetween the display unit and the operating unit either.

Thus, it is provided for example for the display unit to communicatewith the operating unit over a wired connection, that is to say that inthis case the display unit is either arranged fixed to the operatingunit or is movable in relation to the operating unit, but with a wiredconnection.

Another advantageous solution provides for the display unit tocommunicate wirelessly with the operating unit.

The term “wireless communication” should be understood for example ascommunication by way of W-LAN or Bluetooth or another wirelesscommunication network, for example a radio network.

In the case of wireless communication with the operating unit, aplurality of solutions are likewise conceivable as regards thearrangement of the display unit.

It is for example likewise conceivable to arrange the display unit to befixed in this case too.

However, it is particularly advantageous if the display unit is aportable unit that can simply be carried in a mobile manner, by anoperating person.

This is achieved for example in that there serves as the display unit atablet computer or even a mobile telephone or a mobile device of similarconstruction, over which communication with the operating unit ispossible.

In the case of a further alternative, it is likewise preferably providedfor on the one hand a wired display unit that communicates with theoperating unit to be provided, but in addition also an operating unitthat communicates wirelessly with the operating unit to be provided,with the result that the advantages of both solutions are combined.

Moreover, the object stated in the introduction is also achieved bymethods having the features explained below, wherein the individualmethod features have the advantages explained above in conjunction withthe features of the control unit.

In particular, the invention also relates to a method for operating arefrigerant compressor system by means of a control unit, wherein therefrigerant compressor system has a first refrigerant line system forexpanded refrigerant, a second refrigerant line system for compressedrefrigerant, and at least one refrigerant compressor, which operatesbetween the first refrigerant line system and the second refrigerantline system and is driven by its own motor, and wherein the control unithas an operating unit, in which according to the invention the operatingunit stores image element data, for representing at least one componentof the refrigerant compressor system, and, using the image element dataof the at least one component of the refrigerant compressor system, theoperating unit displays this at least one component on the display unit,as a component image element.

Here, it is advantageous if the component includes at least onerefrigerant compressor and in that, using the image element data of theby means of at least one refrigerant compressor, the operating unitrepresents this refrigerant compressor on the display unit, as acompressor image element.

In particular, it is provided for the respective compressor imageelement to be a realistic image of the respective refrigerantcompressor.

As an alternative thereto, it is also conceivable for the respectivecompressor image element to be a stylised image of the respectiverefrigerant compressor.

A favourable solution provides for the component to include at least onerefrigerant line, and, using the image element data of the at least onerefrigerant line, for the operating unit to represent this at least onerefrigerant line on the display unit, as a line image element.

Further, it is favourable if the respective line image element is arealistic image of the at least one refrigerant line.

As an alternative thereto, it is provided for the respective line imageelement to be a stylised image of the at least one refrigerant line.

A further advantageous solution provides for the component to include atleast one sensor, and, using the image element data of the at least onesensor, for the operating unit to represent the at least one sensor onthe display unit, as a sensor image element.

Favourably, it is provided for the sensor image element to be an imageelement that represents the respective sensor in stylised form.

As an alternative thereto, it is provided for the sensor image elementto be an image element that represents the respective sensorsymbolically.

A further solution provides for the operating unit to store for sensordata, and for the operating unit to represent the sensor data on thedisplay unit.

Further, it is advantageous if the sensor values that are detected bythe sensors are represented as a part of the sensor data.

For example, it is provided for the sensor values to be represented by adisplay element of the sensor image element.

However, it is also possible for the sensor values to be representednumerically in the sensor image element.

For the operating person, it is favourable if the sensor image elementis represented at the location of the refrigerant compressor system atwhich the sensor detects the respective sensor value.

A further advantageous solution provides for the component to include atleast one actuator of the refrigerant compressor system, and, using theimage element data of the at least one actuator, for the operating unitto represent this actuator on the display unit, as an actuator imageelement.

In particular, it is favourable if the operating unit stores actuatordata, and in that the operating unit represents the actuator data on thedisplay unit.

Further, it is favourable if the actuator data detected by the actuatorare represented in a manner associated with the actuator image element.

For example, it is provided for the actuator data to be represented by adisplay element.

As an alternative thereto, it is provided for the actuator data to berepresented numerically.

As an alternative or in addition, the object is further achievedaccording to the invention in that the operating unit stores imageelement data for the purpose of representing at least one operatingstate of the refrigerant compressor system, and in that, using the imageelement data of the at least one operating state of the refrigerantcompressor system, the operating unit displays the at least oneoperating state of the refrigerant compressor system on the displayunit, as a state image element.

In particular, it is favourable if the state image element isrepresented in conjunction with the respective component image elementwith which the operating state is associated.

Further, it is advantageous if the state image element is represented asa state field that is associated with the individual component imageelement.

As an alternative or in addition thereto, the object is further achievedaccording to the invention in that the operating unit stores imageelement data for the purpose of representing at least one operatingelement of the operating unit, and in that, using the image element dataof the at least one operating element of the operating unit, theoperating unit displays the operating elements on the display unit, asoperating image elements.

Preferably, for this purpose it is provided for the operating unit tostore image element data for the purpose of representing at least oneoperating state of the respective operating element of the operatingunit, and, using the image element data of the respective operatingstate of the operating element, for the operating unit to display theoperating state of the operating element of the refrigerant compressorsystem on the display unit, as an operating state image element.

Further, it is favourable if the operating state image element isrepresented on the display unit in a manner associated with therespective operating element image element.

A particularly favourable solution provides for the display unit to takea form such that, as a result of a manual interaction with one of theimage elements of the operating unit, a command is producible.

In particular, it is favourable if the display unit takes the form of atouch-detecting display unit, and in that the manual interaction isperformed by manually touching a surface of the display unit in theregion of the image element represented on the display unit.

For example, it is provided here for the transmitted command is acalling up of a further representation of at least one image element.

One possibility provides for the further representation to be a changedrepresentation of the same or a further image element.

It is also possible for the further representation to be an enlargedrepresentation of the same image element.

Furthermore, it is possible for the further representation of therespective image element to be a representation of the respective imageelement with further image elements.

In an advantageous embodiment, it is provided for the display unit tocommunicate with the operating unit over a wired connection.

Another alternative or additional solution provides for the display unitto communicate wirelessly with the operating unit.

In particular in this case, it is possible for the display unit to becarried by an operating person.

Further features and advantages of the invention form the subject matterof the description below and the illustrative drawing of an exemplaryembodiment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an illustration of an exemplary embodiment of a refrigerantcircuit, having a refrigerant compressor system including refrigerantcompressor modules, and a control unit;

FIG. 2 shows an enlarged detail illustration of one of the refrigerantcompressor modules according to FIG. 1;

FIG. 3 shows a schematic illustration of the control unit of therefrigerant compressor system according to the invention;

FIG. 4 shows an illustration of an overview representation that isgenerated on the display unit of the refrigerant compressor systemaccording to the invention, with the image elements used for theoverview representation;

FIG. 5 shows an illustration of a refrigerant compressor module on thedisplay unit, with the image elements used for representing it;

FIG. 6 shows an illustration of a refrigerant compressor on the displayunit, with the image elements used;

FIG. 7 shows an illustration of the image elements that are used on thedisplay unit for representing a lubricant supply system in conjunctionwith a refrigerant line that guides compressed refrigerant, including alubricant separator;

FIG. 8 shows an illustration of the image elements that are used on thedisplay unit for displaying the individual components of the controlunit;

FIG. 9 shows an illustration similar to FIG. 5, with stylised compressorimage elements; and

FIG. 10 shows an illustration similar to FIG. 5, with symbols ascompressor image elements.

DETAILED DESCRIPTION OF THE INVENTION

A refrigerant circuit K that is illustrated schematically in FIG. 1includes a first line system LSE for expanded refrigerant, a second linesystem LSV for compressed refrigerant, and a refrigerant compressorsystem KVA that compresses the expanded refrigerant from the line systemLSE and supplies the compressed refrigerant to the line system LSV forcompressed refrigerant.

Further, the refrigerant circuit K also includes a heat transfer deviceWTV for cooling the refrigerant that has been compressed by therefrigerant compressor system KVA, wherein this heat transfer device isconnected to the line system LSV, an expansion member EXP that isarranged downstream of the heat transfer device WTV and expands thecompressed refrigerant and supplies it to a heat transfer device WTE inwhich the refrigerant that has been cooled by the expansion is able totake up heat.

The refrigerant compressor system KVA that is illustrated by way ofexample in FIG. 1 for its part includes at least one, and in theexemplary embodiment illustrated for example three, refrigerantcompressor modules 10 ₁, 10 ₂ and 10 ₃ that, operating in parallel, arearranged between the first line system LSE for expanded refrigerant andthe second line system LSV for compressed refrigerant, wherein each ofthe refrigerant compressor modules 10 ₁ to 10 ₃ draws refrigerant out ofthe first line system LSE by suction, compresses it and supplies it ascompressed refrigerant to the line system LSV.

Here, as illustrated in FIGS. 1 and 2, each of the refrigerantcompressor modules 10, in this case for example the refrigerantcompressor module 10 ₁, includes a first refrigerant line 12 that isconnected to the first line system LSE for the expanded refrigerant and,in the case of the refrigerant compressor module 10 ₁ illustrated,includes three supply lines 14, 16 and 18, each of which leads to arefrigerant compressor 22, 24, 26 that is respectively driven by its ownmotor 32, 34, 36, preferably an electric motor.

Each of these refrigerant compressors 22, 24, 26 compresses therefrigerant that is moved through the first refrigerant line 12 to ahigher pressure than the pressure in the first refrigerant line 12,wherein this higher pressure is typically an intermediate pressure or ahigh pressure.

The compressed refrigerant is moved out of the respective refrigerantcompressor 22, 24, 26 to a second refrigerant line 42 that includesbranch lines 44, 46, 48 that lead to each of the refrigerant compressors22, 24, 26.

The second refrigerant line 42 for the compressed refrigerant includes alubricant separator, which is designated 52 as a whole and by means ofwhich there is separated off the lubricant entrained in the compressedrefrigerant out of the refrigerant compressors 22, 24, 26, whichrefrigerant accumulates in the lubricant separator 52, for example atthe base, and is moved from the lubricant separator 52 back to theindividual refrigerant compressors 22, 24, 26 for the purpose oflubrication by way of a lubricant supply system 54.

For example, the lubricant supply system 54 here also includes alubricant cooling device 56.

The second refrigerant line 42 further leads the refrigerant that isguided through the lubricant separator 52 to the second refrigerant linesystem LSV.

For the purpose of controlling the individual refrigerant compressormodules 10, a multiplicity of sensors and actuators are associatedtherewith, as illustrated in FIG. 1 with reference to the refrigerantcompressor module 10 ₁.

For the purpose of detecting a temperature of the expanded refrigerantthat is guided by the first refrigerant line 12, a first temperaturesensor 62 is provided, which detects the temperature of the stream ofexpanded refrigerant that is guided in the first refrigerant line 12.

Further, a suction pressure of the individual refrigerant compressors22, 24, 26 is detected, wherein for this purpose a suction pressuresensor 82, 84 is associated for example with each suction side 72, 74,76 of the refrigerant compressors 22, 24, 26.

As an alternative thereto, however, it is also conceivable, instead ofthe individual suction pressure sensors 82, 84, 86, to connect thesuction sides 72, 74, 76 to one another by a pressure-detecting line,and to allocate a common suction pressure sensor for all the suctionsides 72, 74, 76 to the pressure-detecting line, such that an averagedsuction pressure can be detected by this suction pressure sensor.

Further, in each of the refrigerant compressor modules 10 according tothe invention, pressure sides 92, 94, 96 of the refrigerant compressors22, 24, 26 are monitored, wherein for example for this purpose finalpressure sensors 102, 104, 106 are associated with the individualpressure sides 92, 94, 96 of the refrigerant compressors 22, 24, 86.

In order moreover to be able to detect the temperature of the compressedrefrigerant in the second refrigerant line 42, there are associated forexample with the individual branch lines 44, 46, 48 second temperaturesensors 112, 114, 116 that can detect the temperature of the refrigerantthat is compressed by each individual refrigerant compressor 22, 24, 26in each of the individual branch lines 44, 46, 48 individually.

In order to detect the temperature and pressure of the lubricant that ismoved back from the lubricant separator 52 to the individual refrigerantcompressors 22, 24, 26 by way of the lubricant supply system 54, notonly is there associated with the lubricant supply system 54 a lubricanttemperature sensor 122, but also for example a lubricant pressure isdetected by lubricant pressure sensors 124, 126, 128, in particular ineach case close to the lubricant inlet of the individual refrigerantcompressors 22, 24, 26.

To control operation of the individual refrigerant compressor modules10, alongside the described sensors there are also provided actuators,which are for example the individual motors 32, 34, 36 having,associated therewith, motor controllers 132, 134, 136 that take the formfor example of inverters.

Further, there are associated with the individual compressors 22, 24,26, in addition as actuators, control elements 142, 144, 146 by means ofwhich the pressure ratio and/or volume ratio of the individualrefrigerant compressors 22, 24, 26 is controlled.

The individual operating states of the individual refrigerant compressormodules 10 ₁ to 10 ₃ are controlled by a control unit that is designated150 as a whole and is illustrated in conjunction with the refrigerantcompressor modules 10 ₁ to 10 ₃ in FIG. 1 and in detail in FIG. 3.

The individual refrigerant compressor modules 10 ₁ to 10 ₃ arecontrolled on the basis of sensor values of one or more of theabove-mentioned sensors, or on the basis of external control variablesof the refrigerant circuit, for example a pressure of the expandedrefrigerant in the first refrigerant line system LSE or in the heattransfer unit WTE or a pressure of the compressed refrigerant in therefrigerant line system LSV.

For example, as illustrated in FIG. 3, the control unit 150 according tothe invention includes a bus system 152 by means of which a firstcentral processing unit 154 and a second central processing unit 156 andinput/output units 172, 174 and 176 are coupled to one another.

Further, where appropriate in addition, the central processing units 154and 156 are also provided with input/output units 164, 166 that areassociated directly therewith.

The input/output units provide the possibility of making a connectionwith the respective sensors and actuators.

Thus, for example the temperature sensor 62 is connected to theinput/output unit 172.

For the purpose of detecting the suction pressure applied across thesuction sides 72, 74, 76 of the refrigerant compressors 22, 24, 26, arespective one of the suction pressure sensors 82, 84, 86 is connectedto one of the input/output units, so for example the suction pressuresensor 82 is connected to the input/output unit 172, the suctionpressure sensor 84 is connected to the input/output unit 174 and thesuction pressure sensor 86 is connected to the input/output unit 176.

Further, the pressure sides 92, 94, 96 of the refrigerant compressors22, 24, 26 are monitored by the final pressure sensors 102, 104, 106,wherein a respective one of the final pressure sensors is connected toone of the input/output units, so for example the final pressure sensor102 is connected to the input/output unit 172, the final pressure sensor104 is connected to the input/output unit 174 and the final pressuresensor 106 is connected to the input/output unit 176.

Further, the temperature sensors 112, 114, 116 that are associated withthe branch lines 44, 46, 48 of the second refrigerant line 42 areconnected to a respective one of the input/output units 172, 174, 176,so for example the temperature sensor 112 is connected to theinput/output unit 172, the temperature sensor 114 is connected to theinput/output unit 174 and the temperature sensor 116 is connected to theinput/output unit 176.

Similarly, in each case a respective one of the lubricant pressuresensors 124, 126, 128 is connected to one of the input/output units, sofor example the lubricant pressure sensor 124 is connected to theinput/output unit 172, the lubricant pressure sensor 126 is connected tothe input/output unit 174 and the lubricant pressure sensor 128 isconnected to the input/output unit 176.

Further, the lubricant temperature sensor 122 is additionally connectedfor example to the input/output unit 176.

The actuators are also preferably connected by way of the input/outputunits 172, 174, 176. Thus, for example, the individual motor controllers132, 134, 136 are likewise connected to individual input/output units.

For example, the motor controller 132 is connected to the input/outputunit 172, the motor controller 134 is connected to the input/output unit174 and the motor controller 136 is connected to the input/output unit176.

The further actuators, for example the control elements 142, 144, 146for controlling the volume or pressure ratio of the refrigerantcompressors 22, 24, 26, are also connected to different input/outputunits.

Thus, for example, the control element 142 is connected to theinput/output unit 172, the control element 144 is connected to theinput/output unit 174 and the control element 146 is connected to theinput/output unit 176.

As the above exemplary explanation of the connection of the individualsensors and actuators to the input/output units shows, the sensors andactuators that are associated with one of the refrigerant compressors22, 24, 26 are preferably associated with an input/output unit.

This has the advantage that, for example in the event of a failure ofone of the sensors and/or actuators, only one of the refrigerantcompressor units 22, 24, 26 is affected, and so there is the possibilityfor example of continuing to operate the refrigerant compressor module10 concerned using the other two refrigerant compressors 22, 24, 26.

Moreover, the two central processing units 154 and 156 that are providedare preferably used as redundant central processing units, and operateas follows:

In normal operation, the first central processing unit 154 takes overall the control functions for the refrigerant compressor systemaccording to the invention, in particular for all the refrigerantcompressor modules 10 ₁ to 10 ₃, and in so doing in particularcommunicates with the corresponding input/output units 172, 174 and 176by way of the bus system 152.

During this, the second central processing unit 156 operates in astandby state in which there is no communication with the input/outputunits 172, 174 and 176, wherein there is transmitted to the secondcentral processing unit 156 in the standby state, constantly or atsuccessive intervals, a data stream that also transmits all the datadetected by the first central processing unit 154 and stored in a memory194 to a memory 196 of the second central processing unit 156, with theresult that the second central processing unit 156 is at any time ableto take over control of the refrigerant compressor system KVA accordingto the invention with the individual refrigerant compressor modules 10 ₁to 10 ₃.

During this, the second central processing unit 156 constantly monitorsthe first central processing unit 154, in that it checks functioningthereof by transmitting data.

If the second central processing unit 156 establishes that a fault hasoccurred in the first central processing unit 154, the second centralprocessing unit 156 takes over control of the refrigerant compressorsystem KVA according to the invention with the individual refrigerantcompressor modules 10 ₁ to 10 ₃ and for this purpose deactivates thefirst central processing unit 154.

In this way, the control unit 150 as a whole is protected from a failureof the first central processing units 154.

Some of the sensors, for example the sensors 62 and/or the sensors 102,104, 106 that are primarily provided for measurement, and/or alsofurther sensors, are also protectable against failure by the directassociation of redundant sensors, for example the sensors R62 and/or thesensors R102, R104, R106, wherein these redundant sensors R62, R102,R104, R106 may be connected for example in each case both to theinput/output unit 164 and to the input/output unit 166, in order in thisway to be available for interrogation during control of the refrigerantcompressor system KVA by both the first central processing unit 154 orthe second central processing unit 156 if the sensor 62, 102, 104, 106that is in each case primarily provided for measurement fails.

For the purpose of operating the control unit 150, the latter has anoperating unit, which is designated 200 as a whole and is for its partprovided with a wired display unit 202 that communicates with theoperating unit 200, and a memory 204 and a processor 206 for generatingimage elements on the display unit 202, wherein the image elements aregenerated on the display unit 202 by the processor 206, from imageelement data stored in the memory 204.

In addition to the wired display unit 202, a display unit 202′ thatcommunicates wirelessly with the operating unit 200 is provided, andthis communicates with the operating unit for example by way of W-LAN,Bluetooth or another communication network, and in one embodiment may bea suitable mobile telephone or a tablet computer.

Thus, a display unit 202′ is portable and may be used by an operatingperson at any time for the purpose of monitoring and/or functionalcontrol of the refrigerant compressor system KVA.

In this way, the operating unit 200 generates, for example as a firstuser interface, the overview representation that is illustrated in FIG.4, which is a combination of the module image elements B10 ₁, B10 ₂ andB10 ₃, wherein each of these module image elements B10 represents one ofthe refrigerant compressor modules 10 as an image.

Further, the representation according to FIG. 4 also has operating imageelements BB, which represent operating elements by means of whichindividual functions of the control unit 150 are activatable ordeactivatable.

Preferably, it is possible to represent on the display unit 202, inaddition to the operating image element BB, an operating state imageelement BZB, which represents the operating state, for example by adifference between light and dark, or a difference in colour.

Further, the overview representation according to FIG. 4 also includes astate image element BZ that displays for example state data ZD of anoperating state.

In order to be able to switch from the overview representation to otherrepresentations, the display unit 202 is provided with a touch-sensitivesurface 208, with the result that the display unit 202, for example inthe form of a so-called touchscreen, so that it is possible to identifya manual touch, and indeed a movement during a manual touch, as acommand for the operating unit 200.

In this way, it is possible for example to call up as the second userinterface one of the module image elements B10 ₁ to B10 ₃ as an enlargedrepresentation, either by tapping in the region within the respectivemodule image element B10 ₁ to B10 ₃ of the overview representation or bya horizontal or vertical swiping movement or by moving apart two touchpoints within the module image element B10 for the purpose ofestablishing how much it is enlarged.

A module image element BM10 of this kind, which is illustrated in FIG. 5and in that case is illustrated as a whole exclusively on the displayunit 202 - for example the module image element BM10 ₁—is composed, asillustrated in FIG. 5, from a plurality of image elements, for examplethe module image element BM10 is composed of individual realisticcompressor image elements B22, B24 and B26 that represent the individualcompressors 22, 24, 26.

Here, each of the individual compressor image elements B22, B24, B26 canbe, as illustrated by way of example in FIG. 5, a realistic image of therespective refrigerant compressor 22, 24, 26, in order, solely by thisimage element, to make operation and where appropriate also maintenanceeasier for the operating person, since that person need not identify therespective refrigerant compressor 22, 24, 26 by means of a symbol butcan identify it from its actual appearance.

As an alternative thereto, however, it is also possible to use insteadof the realistic image a stylised image of the respective refrigerantcompressor, or indeed a symbol of the respective refrigerant compressor.

Further, the module image element B10 also has line image elements, forexample a line image element B12 for the first refrigerant line 12 and aline image element B42 for the second refrigerant line 42, that can berepresented in connection with the compressor image elements B22, B24and B26 and thus represent the refrigerant compressors 22, 24, 26 inconnection with the first refrigerant line 12 and the second refrigerantline 42.

Moreover, the image element B42 for the second refrigerant line includesfor example also the representation of the lubricant separator 52provided in the second refrigerant line B42.

Further, the module image element B10 includes the representation of theline image element B54, which represents the lubricant supply system 54and thus also shows the supply lines for the lubricant leading to theindividual refrigerant compressors 22, 24, 26.

The module image element B10 further includes, as actuator imageelements, for example the image elements B32, B34 and B36, which for thepurpose of representing the motors 32, 34, 36 are realistic images ofthese motors 32, 34, 36.

As further actuator image elements, the module image element B10 alsoincludes for example the actuator image elements B142, B144 and B146,which represent for example schematic illustrations of the controlelements 142, 144 and 146 for setting the pressure ratio and/or thevolume ratio of the refrigerant compressors 22, 24, 26.

Further, there are also represented, for example in the module imageelement B10 according to FIG. 5, in the form of sensor image elementsB122 and B124, sensor fields having the sensor values that arerepresented therein alongside the line image element B54 for thelubricant supply system 54, in order to inform the relevant operatingperson of the lubricant temperature and the lubricant pressure.

As a result of a further manual intervention, either by tapping one ofthe compressor image elements B22, B24 or B26 or by a vertical orhorizontal swiping movement or by moving apart two touch points in theregion of one of the compressor image elements B22, B24 or B26, it ispossible to represent individually and on an enlarged scale, as a thirduser interface, one of the refrigerant compressors 22, 24, 26, forexample the refrigerant compressor 22 by means of the image element B22,as illustrated in FIG. 6, wherein in this case for example thecompressor image element B22 is represented without the line imageelements B12 and B42.

However, in conjunction with the compressor image element B22 there isalso illustrated an enlarged actuator image element B142, which shows onan enlarged scale the setting of the control element 142 for setting thepressure ratio and/or the volume ratio of the respective refrigerantcompressor, in this case the refrigerant compressor 22.

Further, this representation displays as a sensor image element B82 ananalogue scale of a pressure-measuring instrument, wherein a pointerpoints to the respective sensor value on the analogue scale that wasmeasured by the suction pressure sensor 82.

In the same way, there is represented as a sensor image element B102 ananalogue scale having a pointer, wherein the pointer points to thesensor value that the final pressure sensor 102 detects on the pressureside 92 of the refrigerant compressor 22.

Finally, there is likewise represented as a sensor image element B124 ananalogue scale having a pointer, wherein the pointer points to thesensor value measured by the lubricant pressure sensor 124 at thelubricant supply to the refrigerant compressor 22.

Further, and likewise as a display element having an analogue scale,there are represented in an image element BAD actuator data that showsymbolically the pressure ratio and/or volume ratio at which therefrigerant compressor 22 is operating, on the basis of the setpoint setby the control element 142.

Finally, also represented is the actuator image element B32 that showsthe motor 32 which is driving the first refrigerant compressor 22, andby means of this image element B32, actuator data of the motor 32 arerepresented, also in the form of an image element BAD.

As illustrated in FIG. 7, however, there is also a possibility, bytapping the respective line image element B42 and/or B54 and/or bytapping an operating image element BB provided for this purpose, torepresent, as a further user interface, individual line image elementson the display unit 202, such as the line image element B42 inconnection with the line image element B54, which shows the lubricantsupply system 54 in connection with the second refrigerant line 42, inparticular in connection with the lubricant separator 52, and moreoverthe lubricant cooling device 56 that is arranged in the lubricant supplysystem 54.

Further, there is also represented for example in the representation ofthe line image element B42 and B54, as a sensor image element B122, adisplay image element in which the lubricant temperature measured by thelubricant temperature sensor 122 is shown numerically.

The representation of the image elements B42 and B54 according to FIG. 7is callable for example by tapping with a finger on the operating imageelement BS, which calls up an operating element for the purpose ofrepresenting the elements B42 and B54 having for example the sensorvalue of the lubricant temperature sensor 122.

Moreover, as illustrated in FIG. 8, there is the possibility ofrepresenting as a further user interface, by a control image elementB150, the individual components of the control unit 150, in particularby the control image elements B156 and B154 representing the centralprocessing units 154 and 156, and for example of representing which ofthe processor units 154 and 156 is active and operating.

Further, there is also the possibility of representing, by the controlimage elements B172, B174 and B176, the input/output units 172, 174 and176, and for example of representing the extent to which these areactive and properly functioning.

In a further exemplary embodiment of a control unit according to theinvention, as illustrated in FIG. 9, the refrigerant compressors 22, 24,26 are not represented realistically by the compressor image elementsB22′, B24′, B26′ but in a stylised form for the purpose of reducing thememory capacity occupied by the image element data, wherein therefrigerant compressors 22, 24, 26 are identifiable as such.

In a simplified exemplary embodiment of a control unit according to theinvention, as illustrated in FIG. 10, the refrigerant compressors 22,24, 26 are represented by the compressor image elements B22″, B24″, B26″in the form of symbols, and the image element data require even lessmemory capacity.

1. A control unit for operating a refrigerant compressor system, whereinthe refrigerant compressor system has a first refrigerant line systemfor expanded refrigerant, a second refrigerant line system forcompressed refrigerant, and at least one refrigerant compressor, whichoperates between the first refrigerant line system and the secondrefrigerant line system and is driven by its own motor, and wherein thecontrol unit has an operating unit, the operating unit has a memory forimage element data, for representing at least one component of therefrigerant compressor system, the operating unit has a display unitwhich, using the image element data of the at least one component of therefrigerant compressor system, displays this at least one component onthe display unit, as a component image element.
 2. A control unitaccording to claim 1, wherein the component includes at least onerefrigerant compressor, and in that, using the image element data of theat least one refrigerant compressor, the operating unit represents thisrefrigerant compressor on the display unit, as a compressor imageelement.
 3. A control unit according to claim 1, wherein the componentincludes at least one refrigerant line, and in that, using the imageelement data of the at least one refrigerant line, the operating unitrepresents this at least one refrigerant line on the display unit, as aline image element.
 4. A control unit according to claim 1, wherein thecomponent includes at least one sensor, and in that, using the imageelement data of the at least one sensor, the operating unit representsthe at least one sensor on the display unit, as a sensor image element.5. A control unit according to claim 4, wherein the operating unit has amemory for sensor data, and in that the operating unit represents thesensor data on the display unit.
 6. A control unit according to claim 5,wherein the sensor values that are detected by the sensors arerepresented as a part of the sensor data.
 7. A control unit according toclaim 5, wherein the sensor values are represented by a display elementof the sensor image element.
 8. A control unit according to claim 5,wherein the sensor values are represented numerically in the sensorimage element.
 9. A control unit according to claim 4, wherein thesensor image element is represented at the location of the refrigerantcompressor system at which the sensor detects the respective sensorvalue.
 10. A control unit according to claim 1, wherein the componentincludes at least one actuator of the refrigerant compressor system, andin that, using the image element data of the at least one actuator, theoperating unit represents this actuator on the display unit, as anactuator image element.
 11. A control unit according to claim 10,wherein the operating unit has a memory for actuator data, and in thatthe operating unit represents the actuator data on the display unit. 12.A control unit according to claim 10, wherein the actuator data that aredetected by the actuator are represented in a manner associated with theactuator image element.
 13. A control unit according to claim 12,wherein the actuator data are represented by a display element.
 14. Acontrol unit according to claim 11, wherein the actuator data arerepresented numerically.
 15. A control unit for operating a refrigerantcompressor system, wherein the refrigerant compressor system has a firstrefrigerant line system for expanded refrigerant, a second refrigerantline system for compressed refrigerant, and at least one refrigerantcompressor, which operates between the first refrigerant line system andthe second refrigerant line system and is driven by its own motor, andwherein the control unit has an operating unit, the operating unit has amemory for image element data for the purpose of representing at leastone operating state of the refrigerant compressor system, and using theimage element data of the at least one operating state of therefrigerant compressor system, the operating unit displays the at leastone operating state of the refrigerant compressor system on the displayunit, as a state image element.
 16. A control unit according to claim15, wherein state image element is represented in conjunction with therespective component image element with which the operating state isassociated.
 17. A control unit according to claim 16, wherein the stateimage element is represented as a state field that is associated withthe individual component image elements.
 18. A control unit foroperating a refrigerant compressor system, wherein the refrigerantcompressor system has a first refrigerant line system for expandedrefrigerant, a second refrigerant line system for compressedrefrigerant, and at least one refrigerant compressor, which operatesbetween the first refrigerant line system and the second refrigerantline system and is driven by its own motor, and wherein the control unithas an operating unit, the operating unit has a memory for image elementdata for the purpose of representing at least one operating element ofthe operating unit, and using the image element data of the at least oneoperating element of the operating unit, the operating unit displays theoperating element on the display unit, as an operating image element.19. A control unit according to claim 18, wherein the memory has imageelement data for representing at least one operating state of therespective operating element of the operating unit, and in that, usingthe image element data of the respective operating state of theoperating element, the operating unit displays the respective operatingstate of the operating element of the refrigerant compressor system onthe display unit, as an operating state image element.
 20. A controlunit according to claim 19, wherein the operating state image element isrepresented on the display unit in a manner associated with therespective operating element image element.
 21. A control unit accordingto claim 1, wherein the display unit is designed such that, as a resultof a manual interaction with one of the represented image elements ofthe operating unit, a command is producible.
 22. A control unitaccording to claim 21, wherein the display unit takes the form of atouch-detecting display unit, and in that the manual interaction isperformed by manually touching a surface of the display unit in theregion of the image element represented on the display unit.
 23. Acontrol unit according to claim 21, wherein the transmitted command is acalling up of a further representation of at least one image element.24. A control unit according to claim 23, wherein the furtherrepresentation is a changed representation of the same or a furtherimage element.
 25. A control unit according to claim 1, wherein thedisplay unit communicates with the operating unit over a wiredconnection.
 26. A control unit according to claim 1, wherein the displayunit communicates wirelessly with the operating unit.
 27. A control unitaccording to claim 1, wherein the display unit is a portable unit.
 28. Amethod for operating a refrigerant compressor system by means of acontrol unit, wherein the refrigerant compressor system has a firstrefrigerant line system for expanded refrigerant, a second refrigerantline system for compressed refrigerant, and at least one refrigerantcompressor, which operates between the first refrigerant line system andthe second refrigerant line system and is driven by its own motor, andwherein the control unit has an operating unit, the operating unitstores image element data, for representing at least one component ofthe refrigerant compressor system, using the image element data of theat least one component of the refrigerant compressor system, theoperating unit displays this at least one component on the display unit,as a component image element.
 29. A method according to claim 28,wherein the component includes at least one refrigerant compressor, andin that, using the image element data of the by means of at least onerefrigerant compressor, the operating unit represents this refrigerantcompressor on the display unit, as a compressor image element.
 30. Amethod according to claim 28, wherein the component includes at leastone refrigerant line, and in that, using the image element data of theat least one refrigerant line, the operating unit represents this atleast one refrigerant line on the display unit, as a line image element.31. A method according to claim 28, wherein the component includes atleast one sensor, and in that, using the image element data of the atleast one sensor, the operating unit represents the at least one sensoron the display unit, as a sensor image element.
 32. A method accordingto claim 31, wherein the operating unit stores for sensor data, and inthat the operating unit represents the sensor data on the display unit.33. A method according to claim 32, wherein the sensor values that aredetected by the sensors are represented as a part of the sensor data.34. A method according to claim 32, wherein the sensor values arerepresented by a display element of the sensor image element.
 35. Amethod according to claim 32, wherein the sensor values are representednumerically in the sensor image element.
 36. A method according to claim31, wherein the sensor image element is represented at the location ofthe refrigerant compressor system at which the sensor detects therespective sensor value.
 37. A method according to claim 28, wherein thecomponent includes at least one actuator of the refrigerant compressorsystem, and in that, using the image element data of the at least oneactuator, the operating unit represents this actuator on the displayunit, as an actuator image element.
 38. A method according to claim 37,wherein the operating unit stores actuator data, and in that theoperating unit represents the actuator data on the display unit.
 39. Amethod according to claim 37, wherein the actuator data detected by theactuator are represented in a manner associated with the actuator imageelement.
 40. A method according to claim 39, wherein the actuator dataare represented by a display element.
 41. A method according to claim29, wherein the actuator data are represented numerically.
 42. A methodfor operating a refrigerant compressor system by means of a controlunit, wherein the refrigerant compressor system has a first refrigerantline system for expanded refrigerant, a second refrigerant line systemfor compressed refrigerant, and at least one refrigerant compressor,which operates between the first refrigerant line system and the secondrefrigerant line system and is driven by its own motor, and wherein thecontrol unit has an operating unit, the operating unit stores imageelement data for the purpose of representing at least one operatingstate of the refrigerant compressor system, and using the image elementdata of the at least one operating state of the refrigerant compressorsystem, the operating unit displays the at least one operating state ofthe refrigerant compressor system on the display unit, as a state imageelement.
 43. A method according to claim 42, wherein the state imageelement is represented in conjunction with the respective componentimage element with which the operating state is associated.
 44. A methodaccording to claim 43, wherein the state image element is represented asa state field that is associated with the individual component imageelements.
 45. A method for operating a refrigerant compressor system bymeans of a control unit, wherein the refrigerant compressor system has afirst refrigerant line system for expanded refrigerant, a secondrefrigerant line system for compressed refrigerant, and at least onerefrigerant compressor, which operates between the first refrigerantline system and the second refrigerant line system and is driven by itsown motor, and wherein the control unit has an operating unit, theoperating unit stores image element data for the purpose of representingat least one operating element of the operating unit, and in that, usingthe image element data of the at least one operating element of theoperating unit, the operating unit displays the operating elements onthe display unit, as operating image elements.
 46. A method according toclaim 45, wherein the operating unit stores image element data for thepurpose of representing at least one operating state of the respectiveoperating element of the operating unit, and in that, using the imageelement data of the respective operating state of the operating element,the operating unit displays the operating state of the operating elementof the refrigerant compressor system on the display unit, as anoperating state image element.
 47. A method according to claim 46,wherein the operating state image element is represented on the displayunit in a manner associated with the respective operating element imageelement.
 48. A method according to claim 28, wherein the display unittakes a form such that, as a result of a manual interaction with one ofthe image elements of the operating unit, a command is producible.
 49. Amethod according to claim 48, wherein the display unit takes the form ofa touch-detecting display unit, and in that the manual interaction isperformed by manually touching a surface of the display unit in theregion of the image element represented on the display unit.
 50. Amethod according to claim 48, wherein the transmitted command is acalling up of a further representation of at least one image element.51. A method according to claim 50, wherein the further representationis a changed representation of the same or a further image element. 52.A method according to claim 28, wherein the display unit communicateswith the operating unit over a wired connection.
 53. A method accordingto claim 28, wherein the display unit communicates wirelessly with theoperating unit.
 54. A method according to claim 28, wherein the displayunit is carried by an operating person.